I've never used any but I visited with them at a gun show in Great Falls Montana a couple years ago. They produce a very high quality, product. I was presented with some samples. I took them home and measured and weighed, they were exactly what they were labeled to be. Not many commercial casters are that exacting.
It seems to me that they will do custom sizing too, if you need it.

Yeah, sure, I'll get right on that! All I need is for you to send me all the bullets, primers, brass, powder, dies and data y'all would like me to test for you, as well as a 6 figure stipend, and I'll get back to you.

Anyway... 99 all... I see where they offer bullets for 45LC with gas checks and was thinking on trying some to see if that helps reduce leading issues I have shooting 45 Colt.

Yeah, sure, I'll get right on that! All I need is for you to send me all the bullets, primers, brass, powder, dies and data y'all would like me to test for you, as well as a 6 figure stipend, and I'll get back to you.

Anyway... 99 all... I see where they offer bullets for 45LC with gas checks and was thinking on trying some to see if that helps reduce leading issues I have shooting 45 Colt.

I SAID ALL THIS TO MAKE A POINT. That point is NO ONE can tell you how something is gonna work in YOUR pistol, NO ONE !! YOU are holding the solution to your question in your hand, your gun. There are no freebies and you must pay the piper to learn what is what. NO edjucation is EVER free.
I HAVE already done it in mine and I pay my own bills. I buy 5000 [ from any and all manufacturers...] bullets in ten calibers and weights and test 'em all to see how they do in MY guns. The one thing that I have found that does amaze me is how well those sillyazz MAGMA designs shoot in the majority of ALL my testing when the time is taken to find the best loads for any particular gun. Furthermore, gascheck designs are mostly unneeded IF you take the time to do your homework on the proper sizes for YOUR guns. IF you're the gimme-a-load-and-git-ouuta-the-way reeeloader ,gaschecks can cover up a lot. Sometimes.
And so it goes...

DO NOT TAKE YOUR LOADING DATA OFF THE INTERNET WITHOUT CHECKING IT IN DETAIL AGAINST PRINTED LOADING MANUALS.

KNOW YOUR GUN and it's normal capabilities. Pick a projectile that is of the normal weight that cartridge [ 45COLT-250GR .454"O.D.preferably ]has used over the years. Pick a standard primer used in that caliber. Pick a propellent [ Unique or Universal etc ] that is capable of the normal velocities in that cartridge with that weight of projectile. Pick a propellent from seven[7] sources of loading data; for starting loads toss out the lowest low load and the highest low load, and average the remaining five for your starting load. Load ten[10] cartridges with that load and test them off sandbag rests at 25 yards on a target in two separate 5-shot groups that are simultaneously chrongraphed. We will assume there are no excess pressure signs shown in these first tests
Take your data sources and figure your high load; toss out the highest high load and the lowest low load in the manuals and average the remaining five loads to determine where you do not want to tread.
Further test loads should use about 3/10 of a grain more propellent [ 2/10'S okay too but 5/10 can sometimes surprise when you do not want it...!] and should also be tested in lots of ten for two five-shot groups all over the chronograph screens. BELIEVE ME, all the numbers you'll get off the chrongraph will be importent and tell you much on down the line of further testing. If you see no excess pressure signs load the next ten and then the next etc right up to the average max charge you determined as pressure signs allow. You will learn very soon how YOUR pistol reacts to increased loads and how this affects accuracy. Once you see where testing loads can easily cut what were previously your best groups in half, a big bright bulb will go off above your head; that is the moment you went from reloader to handloader. This whole process is a lot easier than most think and solves the accuracy mystery everytime. SUCH satisfaction. Keep me posted; read all your loading manuals AND I DO MEAN READ THE LOADING DATA FOR ALL THE CARTRIDGES IN THERE as you'll suddenly have some serious epiphanies that'll make you really THINK.
And so it goes...

Okay, copy all and no disagreements there, but let me ask a question or three about leading.

Here's what I thought I understood about leading...

Leading can result from shooting cast bullets that aren't properly sized for the gun being shot from and / or from pushing cast bullets too fast and using lead alloy that its too soft.

While casting, sizing and lubing my own bullets to match my revolvers sounds like fun, it just isn't going to happen anytime soon. Maybe in 20 or so years when I can retire, but who knows if lead will be available to the general public by then, let alone handguns, but I digress.

My initial forey into reloading commercial cast bullets was with Hornadys, but exprienced what I thought was a lot of leading. A Lewis Lead Remover and I got to ge friends.

Anyway, I thought then that using hard cast bullets would be the thing to do. So, mostly I've been using Oregon Trail Laser Cast as they reportedly have a BNH of 25 and seem harder than the Hornadys, but still have leading issues.

Recently, I think I've heard (read) that too hard an alloy can lead to leading?

I suppose its a combination of fit, recipe and alloy hardness, but now I'm confused on where to go next to try to work-up a load that will work in my guns.

Thoughts?

Oh, I've even thought of tumble lubing some commercial cast bullets with Alox, even though they come lubed with ???? in the lube-groove and see how they shoot and lead (or not), but wonder if that would be a stupid thing to do?

A recommendation; Sign on and register at "castboolits.gunloads.com" That is the source of correct information without rumor and inuendo. The answer to you questions may even be in the stickies on that site. Good luck, and enjoy.

DO NOT get hung up on leading as it is mostly a red-herring for folks to bellyache about. LEADING..SO what ?!!! It is of no real consequence and cleans up easily IF you know how to clean a sixgun. A tight patch with HOPPE's will take out the majority of it.
The HORNADY lead bullets are swaged NOT cast and are lots softer than cast bullets. With standard 45COLT loads they can shoot like a million bucks. This also true with the SPEER 250gr LFN swaged bullets and the R-P 255gr LFN bullets which shoot wonderfully well with 800-850FPS 45COLT standard loads. Will they leave a lead wash in the barrel...yep, usually they do but his is also best noted in THE BFD FILE as it too is of NO consequence.
Generally speaking oversized lead bullets shoot the best and leave the least residue behind. I shoot .454" O.D. bullets in all my guns including those " tight RUGER 45" pistols and they shoot very well indeed. Let me note also that ALL my COLT SAA and NF sixguns shoot .452" bullets just fine also with only a modicrum of load developement.
What the boys who scream the loudest about " leading " do not tell you is all those jacketed bullets they shoot cost ten times as much as good cast bullets and leave copper fouling behing that is ten times harder to remove that any leading !!!
I am quite enamored with the OREGON TRAIL cast bullets and have shot many thousands of 'em with every satisfaction in 44 and 45 calibers in all my 44 and 45 caliber pistols and the 44 and 45 caliber carbines. IF I stuffed the leading in your eye from those bullets you'd barely blink...maybe once.
HARD CAST bullets should be shot with the 45COLT medium loads[ 950-1000fps ] to shoot their cleanest best.
If you want to use the cleanest shooting, most classic , accurate, and deadly 45COLT bullet of aLL time you will buy or make bullets in the lyman 454424 mould. The new moulds are 452424 but look out for the earlier 454424 mould to buy. You can also buy these and I would suggest you always buy them in .454" O.D. This bullet was designed by ELMER KEITH [ ...genuflect here..] and NO 45 COLT bullet is it's equal. NONE !!!! IF you buy these ask the maker to lube them with JAVALINA lube or its 4138ALOX/BEESWAX equal.
AND finally we have to note here that some guns are natural leaders due to something goofy in their makeup somewhere; THIS IS RARE !! MOST leading is caused by the ignorence of the folks assembling the ammunition. It is no more difficult to do it right, ol' pard !!!
And so it goes...